The idea I have from your request is to have some "scope fixing".
It may fit some need I have heard of
As I imagine it :
- Add a button "fix scope" on a version

- When scope of a version is fixed :
=> no new item can be linked to this version as target version
=> no item can be removed from this target version
=> "Description" section is locked for all items linked to this version as target version (not only tickets !)
=> "Treatment" section is open for all items linked to this version as target version, except "target version"

) and possibly estimated work, priority, initial due date time and some others to define.
This way you really fix a scope :
=> not only fix some elements, but also fix the list of the elements in the scope
=> not blocking resource to continue to work on elements of the scope
What do you thing about this solution ?